The invention relates to an automotive milling machine for machining ground surfaces, particularly roadways, as well as to a method for the disposal of dusts and fumes at a milling machine, which are produced during the milling.
Such milling machines are also called road milling machines.
A front loader milling machine, for example, is known from DE-A-39 03 482 or DE-A 38 31 161. The known milling machines comprise an automotive running gear with a pair of front wheels and a pair of rear wheels. The running gear supports a machine frame in which a milling drum is supported transverse to the traveling direction. To achieve a transportation of the milled-off material that is as complete as possible, the milling drum is typically surrounded by a housing in which the wall pointing towards the traveling direction is configured as a covering shield with a passage opening for the milled-off material. That wall that is the rear one in traveling direction is configured as a stripper and pressed against the milled surface to seal the drum box to the rear in order to supply the milled-off material completely to transportation. The milling drum throws the material worked off by the milling drum onto a first band conveyor which transfers the worked-off material onto a stacker belt at the front end of the milling machine, which is pivotable with respect to its inclination and laterally for the transport onto a floor of a truck.
Another embodiment of these road milling machines, the so-called rear loader milling machine, is known from DE-A 34 05 473, for example. Here, the passage opening for the milled-off material is located in the wall of the drum housing pointing toward the direction opposite to the traveling direction and also being configured as a stripper. The material milled off by the milling roll is directly transferred onto the band conveyor serving as stacker belt and being arranged at the rear end of the milling machine to transport it onto a truck. Like the stacker belt of the front loader milling machine, the stacker belt of the rear loader milling machine may also be pivotable in its inclination and laterally.
The milling drum of such road milling machines is fitted with chisel tools forming a conveying helix transporting the milled-off material to the passage opening of the covering shield.
By milling off the ground surface and by transporting the milled-off material, dusts and fumes are produced which may impair the operativeness of the conveying devices, on the one hand, and worsen the working conditions for the machine operator on the driver stand and for the remaining operating personnel about the milling machine, on the other hand, and possibly even be an obstacle to the view for the traffic that is possibly passing.
From EP 0 971 075, it is already known to provide the band conveyors of a milling machine with a hood, to suck off the produced dust at the milling drum and under the hood of the band conveyors opposite to the transport direction and to dispose of it via a blower and a filtering means at the rear end of the milling machine. It is disadvantageous that the sucking is effected at the band conveyors opposite to the transport direction. Due to the fact that the dusty air is sucked off rearward and opposite to the actual transport direction of the material, considerable additional efforts for the conversion of the machine and a distinctly higher air output of the blower are required. The use of a radial fan at the rear end of the milling machine has the disadvantage that it is not possible to achieve a sufficiently high airflow at the band conveyors that are at the front in the direction of travel. Finally, the particles discarded at the blower and the cyclone filter are thrown onto the ground surface again whereby the ground surface just milled off is soiled again. The cyclone filter provided at the rear end of the machine is only able to segregate the coarser particles but not the respirable fine dusts so that the arrangement of the air outlet at the rear end of the milling machine is arranged too close to the driver stand. The same applies to a mesh-shaped filter that is not able to segregate respirable dusts either. Another disadvantage of prior art consists in that dusts and fumes are blown off at the rear end of the milling machine near the driver stand and that, moreover, dusts are inevitably produced anew when the milled-off material is thrown off at the front band conveyor.